让用户“关闭”窗口，但实际上只是隐藏它。

在窗口的OnClosing事件中，隐藏已经可见的窗口:

    If Me.Visibility = Windows.Visibility.Visible Then
        Me.Visibility = Windows.Visibility.Hidden
        e.Cancel = True
    End If

每次后台线程执行时，重新显示后台UI窗口:

    w.Visibility = Windows.Visibility.Visible
    w.Show()

当终止程序执行时，确保所有窗口都是/可以关闭的:

Private Sub CloseAll()
    If w IsNot Nothing Then
        w.Visibility = Windows.Visibility.Collapsed ' Tell OnClosing to really close
        w.Close()
    End If
End Sub

要设置的属性是=> WindowStyle="None"

<Window x:Class="mdaframework.MainWindow"
            xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
            xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
            Title="Start" Height="350" Width="525" ResizeMode="NoResize"  WindowStartupLocation="CenterScreen" WindowStyle="None">

我只是使用交互性行为(你需要引用System.Windows.Interactivity)添加了我对Joe White的答案的实现。

代码:

public class HideCloseButtonOnWindow : Behavior<Window>
{
    #region bunch of native methods

    private const int GWL_STYLE = -16;
    private const int WS_SYSMENU = 0x80000;

    [DllImport("user32.dll", SetLastError = true)]
    private static extern int GetWindowLong(IntPtr hWnd, int nIndex);

    [DllImport("user32.dll")]
    private static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);

    #endregion

    protected override void OnAttached()
    {
        base.OnAttached();
        AssociatedObject.Loaded += OnLoaded;
    }

    protected override void OnDetaching()
    {
        AssociatedObject.Loaded -= OnLoaded;
        base.OnDetaching();
    }

    private void OnLoaded(object sender, RoutedEventArgs e)
    {
        var hwnd = new WindowInteropHelper(AssociatedObject).Handle;
        SetWindowLong(hwnd, GWL_STYLE, GetWindowLong(hwnd, GWL_STYLE) & ~WS_SYSMENU);
    }
}

用法:

<Window x:Class="WpfApplication2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
        xmlns:w="clr-namespace:WpfApplication2">

    <i:Interaction.Behaviors>
        <w:HideCloseButtonOnWindow />
    </i:Interaction.Behaviors>

</Window>

使用这个，从https://stephenhaunts.com/2014/09/25/remove-the-close-button-from-a-wpf-window修改:

using System;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Input;
using System.Windows.Interop;
using System.Windows.Media;

namespace Whatever
{
    public partial class MainMenu : Window
    {
        private const int GWL_STYLE = -16;
        private const int WS_SYSMENU = 0x00080000;

        [DllImport("user32.dll", SetLastError = true)]
        private static extern int GetWindowLongPtr(IntPtr hWnd, int nIndex);

        [DllImport("user32.dll")]
        private static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);

        public MainMenu()
        {
             InitializeComponent();
             this.Loaded += new RoutedEventHandler(Window_Loaded);
        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            var hwnd = new WindowInteropHelper(this).Handle;
            SetWindowLongPtr(hwnd, GWL_STYLE, GetWindowLongPtr(hwnd, GWL_STYLE) & ~WS_SYSMENU);
        }  

    }
}

下面是关于禁用关闭和最大化/最小化按钮，它实际上并没有删除按钮(但它确实删除了菜单项!)标题栏上的按钮以禁用/灰色状态绘制。(我还没准备好自己接管所有的功能^^)

这与Virgoss解决方案略有不同，因为它删除了菜单项(如果需要的话，还有后面的分隔符)，而不是仅仅禁用它们。它不同于Joe Whites的解决方案，因为它没有禁用整个系统菜单，所以，在我的情况下，我可以保留最小化按钮和图标。

下面的代码还支持禁用最大化/最小化按钮，因为与关闭按钮不同，从菜单中删除条目不会导致系统呈现按钮“禁用”，即使删除菜单项会禁用按钮的功能。

这对我很管用。YMMV。

    using System;
    using System.Collections.Generic;
    using System.Text;

    using System.Runtime.InteropServices;
    using Window = System.Windows.Window;
    using WindowInteropHelper = System.Windows.Interop.WindowInteropHelper;
    using Win32Exception = System.ComponentModel.Win32Exception;

    namespace Channelmatter.Guppy
    {

        public class WindowUtil
        {
            const int MF_BYCOMMAND = 0x0000;
            const int MF_BYPOSITION = 0x0400;

            const uint MFT_SEPARATOR = 0x0800;

            const uint MIIM_FTYPE = 0x0100;

            [DllImport("user32", SetLastError=true)]
            private static extern uint RemoveMenu(IntPtr hMenu, uint nPosition, uint wFlags);

            [DllImport("user32", SetLastError=true)]
            private static extern IntPtr GetSystemMenu(IntPtr hWnd, bool bRevert);

            [DllImport("user32", SetLastError=true)]
            private static extern int GetMenuItemCount(IntPtr hWnd);

            [StructLayout(LayoutKind.Sequential)]
            public struct MenuItemInfo {
                public uint   cbSize;
                public uint   fMask;
                public uint   fType;
                public uint   fState;
                public uint   wID;
                public IntPtr hSubMenu;
                public IntPtr hbmpChecked;
                public IntPtr hbmpUnchecked;
                public IntPtr dwItemData; // ULONG_PTR
                public IntPtr dwTypeData;
                public uint   cch;
                public IntPtr hbmpItem;
            };

            [DllImport("user32", SetLastError=true)]
            private static extern int GetMenuItemInfo(
                IntPtr hMenu, uint uItem,
                bool fByPosition, ref MenuItemInfo itemInfo);

            public enum MenuCommand : uint
            {
                SC_CLOSE = 0xF060,
                SC_MAXIMIZE = 0xF030,
            }

            public static void WithSystemMenu (Window win, Action<IntPtr> action) {
                var interop = new WindowInteropHelper(win);
                IntPtr hMenu = GetSystemMenu(interop.Handle, false);
                if (hMenu == IntPtr.Zero) {
                    throw new Win32Exception(Marshal.GetLastWin32Error(),
                        "Failed to get system menu");
                } else {
                    action(hMenu);
                }
            }

            // Removes the menu item for the specific command.
            // This will disable and gray the Close button and disable the
            // functionality behind the Maximize/Minimuze buttons, but it won't
            // gray out the Maximize/Minimize buttons. It will also not stop
            // the default Alt+F4 behavior.
            public static void RemoveMenuItem (Window win, MenuCommand command) {
                WithSystemMenu(win, (hMenu) => {
                    if (RemoveMenu(hMenu, (uint)command, MF_BYCOMMAND) == 0) {
                        throw new Win32Exception(Marshal.GetLastWin32Error(),
                            "Failed to remove menu item");
                    }
                });
            }

            public static bool RemoveTrailingSeparator (Window win) {
                bool result = false; // Func<...> not in .NET3 :-/
                WithSystemMenu(win, (hMenu) => {
                    result = RemoveTrailingSeparator(hMenu);
                });
                return result;
            }

            // Removes the final trailing separator of a menu if it exists.
            // Returns true if a separator is removed.
            public static bool RemoveTrailingSeparator (IntPtr hMenu) {
                int menuItemCount = GetMenuItemCount(hMenu);
                if (menuItemCount < 0) {
                    throw new Win32Exception(Marshal.GetLastWin32Error(),
                        "Failed to get menu item count");
                }
                if (menuItemCount == 0) {
                    return false;
                } else {
                    uint index = (uint)(menuItemCount - 1);
                    MenuItemInfo itemInfo = new MenuItemInfo {
                        cbSize = (uint)Marshal.SizeOf(typeof(MenuItemInfo)),
                        fMask = MIIM_FTYPE,
                    };

                    if (GetMenuItemInfo(hMenu, index, true, ref itemInfo) == 0) {
                        throw new Win32Exception(Marshal.GetLastWin32Error(),
                            "Failed to get menu item info");
                    }

                    if (itemInfo.fType == MFT_SEPARATOR) {
                        if (RemoveMenu(hMenu, index, MF_BYPOSITION) == 0) {
                            throw new Win32Exception(Marshal.GetLastWin32Error(),
                                "Failed to remove menu item");
                        }
                        return true;
                    } else {
                        return false;
                    }
                }
            }

            private const int GWL_STYLE = -16;

            [Flags]
            public enum WindowStyle : int
            {
                WS_MINIMIZEBOX = 0x00020000,
                WS_MAXIMIZEBOX = 0x00010000,
            }

            // Don't use this version for dealing with pointers
            [DllImport("user32", SetLastError=true)]
            private static extern int SetWindowLong (IntPtr hWnd, int nIndex, int dwNewLong);

            // Don't use this version for dealing with pointers
            [DllImport("user32", SetLastError=true)]
            private static extern int GetWindowLong (IntPtr hWnd, int nIndex);

            public static int AlterWindowStyle (Window win,
                WindowStyle orFlags, WindowStyle andNotFlags) 
            {
                var interop = new WindowInteropHelper(win);

                int prevStyle = GetWindowLong(interop.Handle, GWL_STYLE);
                if (prevStyle == 0) {
                    throw new Win32Exception(Marshal.GetLastWin32Error(),
                        "Failed to get window style");
                }

                int newStyle = (prevStyle | (int)orFlags) & ~((int)andNotFlags);
                if (SetWindowLong(interop.Handle, GWL_STYLE, newStyle) == 0) {
                    throw new Win32Exception(Marshal.GetLastWin32Error(),
                        "Failed to set window style");
                }
                return prevStyle;
            }

            public static int DisableMaximizeButton (Window win) {
                return AlterWindowStyle(win, 0, WindowStyle.WS_MAXIMIZEBOX);
            }
        }
    }

用法:这必须在初始化源代码后执行。一个好地方是使用窗口的SourceInitialized事件:

Window win = ...; /* the Window :-) */
WindowUtil.DisableMaximizeButton(win);
WindowUtil.RemoveMenuItem(win, WindowUtil.MenuCommand.SC_MAXIMIZE);
WindowUtil.RemoveMenuItem(win, WindowUtil.MenuCommand.SC_CLOSE);
while (WindowUtil.RemoveTrailingSeparator(win)) 
{
   //do it here
}

要禁用Alt+F4功能，简单的方法是连接取消事件，并使用设置一个标志，当你真的想关闭窗口。

这不会隐藏按钮，但会阻止用户通过关闭窗口向前移动。

protected override void OnClosing(System.ComponentModel.CancelEventArgs e)
{            
    if (e.Cancel == false)
    {
        Application.Current.Shutdown();
    }
}